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Sodium nitroprusside Intravenous for Adults
Who can administer
Administration RESTRICTED - see Appendix 1
Important information
- Flush: Do not flush the administration set. After the infusion is discontinued, disconnect the giving set, aspirate the catheter contents and flush the cannula/catheter with sodium chloride or glucose 5% (ref 4,5)
- Consider cyanide toxicity if patients with hepatic or renal impairment, or in rates exceeding 3 micrograms/kg/minute for more than 72 hours (ref 1)
- Unlicensed preparation
- Sodium nitroprusside produces an immediate response of short duration; within a few (1 to 10) minutes of discontinuation of the infusion, the patient's blood pressure returns to initial levels
- For Y-site compatibility see below
Available preparations
Sodium Nitroprusside 50mg per 2ml vial (Sandoz brand)- with solvent ampoule provided
Reconstitution
Dilute the contents of the vial using the solvent ampoule provided
Draw up solvent ampoule using a 5 micron filter needle
Dilute further prior to administration
Infusion fluids
Glucose 5% only
Methods of intravenous administration
Continuous intravenous infusion (administer using an electronically controlled infusion device)
- Add 50mg to 250ml infusion fluid (200 micrograms/ml) (ref 6)
- The infusion device, and the giving set must be covered to protect the drug from light - silver wrapping is provided in the pack to allow this
- Administer at a suitable rate as per 'dose' below
- The prepared solution has a very faint brownish tint - if it is highly coloured it should be discarded
- Fluid restriction: can prepare a 1mg per 1ml solution (central line only) (ref 3,4)
Dose in adults
| Using a 50mg in 250ml strength | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dose in micrograms/kg/minute | 0.1 | 0.3 | 0.5 | 1 | 1.5 | 2 | 2.5 | 3 | 3.5 | 4 | 5 | 6 | 7 | 8 |
| Weight in kg (below) | Rate below is in ml per hour | |||||||||||||
| 40kg | 1.2 | 3.6 | 6 | 12 | 18 | 24 | 30 | 36 | 42 | 48 | 60 | 72 | 84 | 96 |
| 45kg | 1.4 | 4.1 | 6.8 | 13.5 | 20.3 | 27 | 33.8 | 40.5 | 47.3 | 54 | 67.5 | 81 | 94.5 | 108 |
| 50kg | 1.5 | 4.5 | 7.5 | 15 | 22.5 | 30 | 37.5 | 45 | 52.5 | 60 | 75 | 90 | 105 | 120 |
| 55kg | 1.7 | 5 | 8.3 | 16.5 | 24.8 | 33 | 41.3 | 49.5 | 57.8 | 66 | 82.5 | 99 | 115.5 | 132 |
| 60kg | 1.8 | 5.4 | 9 | 18 | 27 | 36 | 45 | 54 | 63 | 72 | 90 | 108 | 126 | 144 |
| 65kg | 2 | 5.9 | 9.8 | 19.5 | 29.3 | 39 | 48.8 | 58.5 | 68.3 | 78 | 97.5 | 117 | 136.5 | 156 |
| 70kg | 2.1 | 6.3 | 10.5 | 21 | 31.5 | 42 | 52.5 | 63 | 73.5 | 84 | 105 | 126 | 147 | 168 |
| 75kg | 2.3 | 6.8 | 11.3 | 22.5 | 33.8 | 45 | 56.3 | 67.5 | 78.8 | 90 | 112.5 | 135 | 157.5 | 180 |
| 80kg | 2.4 | 7.2 | 12 | 24 | 36 | 48 | 60 | 72 | 84 | 96 | 120 | 144 | 168 | 192 |
| 85kg | 2.6 | 7.7 | 12.8 | 25.5 | 38.3 | 51 | 63.8 | 76.5 | 89.3 | 102 | 127.5 | 153 | 178.5 | 204 |
| 90kg | 2.7 | 8.1 | 13.5 | 27 | 40.5 | 54 | 67.5 | 81 | 94.5 | 108 | 135 | 162 | 189 | 216 |
| 95kg | 2.9 | 8.6 | 14.3 | 28.5 | 42.8 | 57 | 71.3 | 85.5 | 99.8 | 114 | 142.5 | 171 | 199.5 | 228 |
| 100kg | 3 | 9 | 15 | 30 | 45 | 60 | 75 | 90 | 105 | 120 | 150 | 180 | 210 | 240 |
| 105kg | 3.2 | 9.5 | 15.8 | 31.5 | 47.3 | 63 | 78.8 | 94.5 | 110.3 | 126 | 157.5 | 189 | 220.5 | 252 |
| 110kg | 3.3 | 9.9 | 16.5 | 33 | 49.5 | 66 | 82.5 | 99 | 115.5 | 132 | 165 | 198 | 231 | 264 |
| 115kg | 3.5 | 10.4 | 17.3 | 34.5 | 51.8 | 69 | 86.3 | 103.5 | 120.8 | 138 | 172.5 | 207 | 241.5 | 276 |
| 120kg | 3.6 | 10.8 | 18 | 36 | 54 | 72 | 90 | 108 | 126 | 144 | 180 | 216 | 252 | 288 |
Hypertensive crisis (doses are in micrograms/kg/minute)
- Initial dose is normally within the range of 0.5 to 1.5 micrograms/kg/minute, lower initial doses of 0.3 to 0.5 micrograms/kg/minute have also been used (ref 1,2,7)
- This can be adjusted in increments of 0.5 micrograms/kg/minute every three to five minutes (ref 6)
- Dose range 0.5 to 8 micrograms/kg/minute (average dose required 3 micrograms/kg/minute
- Higher doses up to 10 microgram/kg/minute may be needed for a maximum time of 10 minutes (ref 1)
- Action occurs within 1 to 2 minutes (ref 6)
- Excessive hypotension resulting in compromised perfusion of vital organs must be avoided (ref 1)
Heart failure (doses are in micrograms/minute)
- Initial dose should be between 10 to 15 micrograms/minute, increased every 5 to 10 minutes to the normal range of 10 to 200 micrograms/minute, to obtain the desired response
- Usually for maximum of three days for this indication (ref 7)
Controlled hypotension during general anaesthesia (doses are in micrograms/kg/minute)
- Maximum dose of 1.5 microgram/kg/minute is recommended (ref 2,7)
Monitoring
- Monitor patients for signs of cyanide toxicity - which may present as symptoms of hypothyroidism
Storage
- Store below 250C
- Following reconstitution, protect the bag from light by covering with aluminium foil (supplied with product) or other opaque material as soon as possible. Under these conditions the 50mg in 250ml glucose 5% infusion is stable for 24 hours (ref 5). Discard the bag if the solution develops a strong discolouration (a faint brown tint is acceptable to use).
References
SPC Sandoz brand Nitroprussiat Fides 50mg/2ml (PIL May 2017)
(1) Uptodate accessed online 22/10/2021
(2) Martindale accessed online 21/10/2021
(3) Minimum infusion volumes UKCPA version 4.4 December 2012
(4) Injectable Medicines Guide, Medusa accessed online 21/10/2021
(5) Injectable Medicines Administration Guide UCL Hospitals 3rd ed
(6) American Heart Association ACLS core drugs 2006
(7) BNF online accessed 16/11/2021
Therapeutic classification
Vasodilator antihypertensive